Javacool just released another, improved version from File Checker: v1.6

In his opinion, this is the most stable, fastest, and best release of FileChecker yet.
Even if you haven't had any problems with previous versions of FileChecker, he would recommend upgrading because the new version uses even less processing time in
many cases (on a couple systems it went down from 2%, running at scanning every 1 second, to 1-1.5%).

New features/bug fixes/changes:

LATEST UPDATE (1.6):
-NEW: All current known issues fixed! (This includes false detections on some systems in certain instances - this is completely fixed)
-NEW: Fixed another instance of the run-time error 6 bug.
-NEW: SMTP ALERT ENGINE! (Send e-mail alerts for deletions, checksum changes, etc.)
-NEW: Fixed problems with any checksum scanning time above 2 minutes not working correctly - you can now set it for as long as you like
-NEW: Fixed specific problems on certain system configurations
-NEW: Numerous bug fixes and error fixes (too many to list)
-NEW: Donation information
-NEW: Tutorial for beginning users

New users may find the FileChecker tutorial as a good guide to getting started configuring and setting up FileChecker. (It also includes a list of recommendations
of files you should add to your FileChecker watch-list).